Part of the The Plenum Chemical Engineering Series book series (PCES)
The mean free path (mfp) of molecules increases when the gas pressure is reduced, and at low enough pressure the (mfp) is so large that the molecules begin to bounce from wall to wall of the flow channel rather than collide with each other. When this happens the character of the flow changes. Thus, different flow regimes are encountered depending on the value of the ratio
where Kn is called the Knudsen number.
KeywordsLaminar Flow Flow Regime Leak Rate Vacuum Pump Vacuum System
Unable to display preview. Download preview PDF.
References and Further Readings
- A. S. D. Barrett, and B. D. Power, in Chemical Engineering Practice (H. W. Cremer and T. Davies, eds.), Vol. 5, Academic Press, New York (1958).Google Scholar
- S. Dushman, Scientific Foundation of Vacuum Technique, Wiley, New York (1949). Complete and comprehensive.Google Scholar
- R. Loevinger, in Vacuum Equipment and Technique, (A. Guthrie and R. K. Wakerling, eds.), Chapter 1, McGraw-Hill, New York (1949). A nice, simple treatment of pumping systems.Google Scholar
© Springer Science+Business Media New York 1998